| 摘要 |
PURPOSE:To manufacture foamed synthetic resin having a small thermal conductivity by pressurizing a material tank of a foaming machine by low-boiling halogenated hydrocarbon. CONSTITUTION:A material tank of a foaming machine employed for manufacture is pressurized by low-boiling halogenated hydrocarbon of which the boiling point at one atm. is -30 deg.C or below. Since the vapor pressure of this low-boiling halogenated hydrocarbon at a room temperature is 4 atm. or above, it can be used as a pressure gas in place of air or nitrogen, and monochlorotrifluoromethane, tetrafluoromethane, monofluoroethane, etc., can be mentioned as concrete examples thereof. This low-boiling halogenated hydrocarbon is a compound of which the thermal conductivity is 0.015kcal/m h deg.C or below, or the like, and its effect of raising (deteriorating) the thermal conductivity is small even when it is taken in a synthetic foamed body, thus enabling the reduction of the thermal conductivity of the foamed body. |
